Collision course: Whales and ships in SoCal

A fin whale was caught on the bow of a ship in Long Beach Harbor in October 2008, part of what marine ecologists said is an increasing problem with whale-vessel collisions in Southern California. The carcass of a different fin whale that had been hit by a ship washed ashore in Point Loma late last year.
— Alisa Schulman-Janiger

A fin whale was caught on the bow of a ship in Long Beach Harbor in October 2008, part of what marine ecologists said is an increasing problem with whale-vessel collisions in Southern California. The carcass of a different fin whale that had been hit by a ship washed ashore in Point Loma late last year.
/ Alisa Schulman-Janiger

When the carcass of a fin whale washed up in Point Loma late last year, it was a small sign of a much larger problem that marine ecologists say has increased globally along with maritime commerce and whale populations.

A necropsy revealed the creature suffered numerous bone fractures, confirming that it was one of more than 60 large whales documented to have been hit by ships near California’s coast since 2001. The count includes 15 reported in San Diego County, which ranks with Los Angeles County as the places in the state with the most known ship-strikes.

Researchers said the count might be just 10 percent of the actual total because some whales sink quickly and others float out to sea undetected. It took the deaths of four blue whales five years ago for the issue to surface in the regional consciousness, even though ship strikes have been occasionally reported for decades. Blues are among the most iconic and endangered sea creatures — a majestic symbol of the coast — and the cluster of fatalities catalyzed interest.

“What we have is the abundance of whales has gone up, but also the number of big fast ships has grown,” said Wayne Perryman, a whale researcher at the federal Southwest Fisheries Science Center in La Jolla. “In some years, the primary prey source (for whales) ends up being right in the middle of the shipping lane.”

These days, government agencies and nonprofit groups are working on several initiatives aimed at reducing whale-ship run-ins, which some now characterize as a major cause of death for certain species.

Shipstrikes

Gray whales, which migrate past San Diego each year, are healthy enough that current levels of ship strikes aren’t deemed to be a big deal for the overall population. But marine ecologists said collisions with vessels may be slowing the recovery of endangered blue whales on the West Coast and endangered right whales on the East Coast.

The incidents are among many that highlight a growing challenge nationwide: Nearshore waters have become so congested that they can’t accommodate existing users without conflict. Add to that difficulties in predicting animal behavior, and finding management solutions is daunting.

There are several possible explanations for why local numbers of ship strikes are relatively high. They include local shores that are more easily accessible to observers who spot the dead whales than some other parts of the state, and the potential that the animals drift here from the north. The San Diego count also may be skewed by the Navy’s rigorous documentation of whales hit by ships, an approach that isn’t always shared by other vessel operators.

“Ships strikes are fascinating — fascinating in a bad way — because they are so complicated. There are so many different factors,” said Jessica Redfern, ecosystem studies program leader for the science center, run by the National Marine Fisheries Service. “In my mind, a really great starting place is reducing that overlap between ships and whales.”

Coast Guard officials recently proposed altering shipping lanes for the ports of Los Angeles and Long Beach, in part to avoid prime whale habitat around the Channel Islands National Marine Sanctuary.